emails: Update context/content for stream to channel rename.

In the missed message email, updates "stream_name" context variable
to be "channel_name". This varible is part of some translated
strings in the email's content.

In onboarding zulip topics email, updates content references to
streams to use channels instead for translated strings. Also,
updates "move_topic_to_different_stream_link" context variable to
be "move_channels_link".

Does not yet update the image used in the onboarding topics email
as that will be updated as part of the help center changes for
this rename.

Part of stream to channel rename project.

templates/zerver/emails/missed_message.html

@@ -30,17 +30,17 @@
     {% elif mentioned_user_group_name %}
     {% trans %}You are receiving this because @{{ mentioned_user_group_name }} was mentioned.{% endtrans %}<br />
     {% elif topic_wildcard_mentioned_in_followed_topic %}
-    {% trans %}You are receiving this because all topic participants were mentioned in #{{ stream_name }} > {{ topic_name }}.{% endtrans %}<br />
+    {% trans %}You are receiving this because all topic participants were mentioned in #{{ channel_name }} > {{ topic_name }}.{% endtrans %}<br />
     {% elif stream_wildcard_mentioned_in_followed_topic %}
     {% trans %}You are receiving this because you have wildcard mention notifications enabled for topics you follow.{% endtrans %}<br />
     {% elif topic_wildcard_mentioned %}
-    {% trans %}You are receiving this because all topic participants were mentioned in #{{ stream_name }} > {{ topic_name }}.{% endtrans %}<br />
+    {% trans %}You are receiving this because all topic participants were mentioned in #{{ channel_name }} > {{ topic_name }}.{% endtrans %}<br />
     {% elif stream_wildcard_mentioned %}
-    {% trans %}You are receiving this because everyone was mentioned in #{{ stream_name }}.{% endtrans %}<br />
+    {% trans %}You are receiving this because everyone was mentioned in #{{ channel_name }}.{% endtrans %}<br />
     {% elif followed_topic_email_notify %}
     {% trans %}You are receiving this because you have email notifications enabled for topics you follow.{% endtrans %}<br />
     {% elif stream_email_notify %}
-    {% trans %}You are receiving this because you have email notifications enabled for #{{ stream_name }}.{% endtrans %}<br />
+    {% trans %}You are receiving this because you have email notifications enabled for #{{ channel_name }}.{% endtrans %}<br />
     {% endif %}
     {% if reply_to_zulip %}
     {% trans notif_url=realm_uri + "/#settings/notifications" %}Reply to this email directly, <a href="{{ narrow_url }}">view it in {{ realm_name }} Zulip</a>, or <a href="{{ notif_url }}">manage email preferences</a>.{% endtrans %}

templates/zerver/emails/missed_message.subject.txt

@@ -9,8 +9,8 @@
         advantage of this to retain thread continuity in email notifications
         even after a topic is resolved.
         #}
-        {% if topic_resolved %}{% trans %}[resolved] #{{ stream_name }} > {{ topic_name }}{% endtrans %}
-        {% else %}#{{ stream_name }} > {{ topic_name }}
+        {% if topic_resolved %}{% trans %}[resolved] #{{ channel_name }} > {{ topic_name }}{% endtrans %}
+        {% else %}#{{ channel_name }} > {{ topic_name }}
         {% endif %}
     {% endif %}
 {% else %}

templates/zerver/emails/missed_message.txt

@@ -26,17 +26,17 @@ See {{ alert_notif_url }} for more details.
 {% elif mentioned_user_group_name %}
 {% trans %}You are receiving this because @{{ mentioned_user_group_name }} was mentioned.{% endtrans %}
 {% elif topic_wildcard_mentioned_in_followed_topic %}
-{% trans %}You are receiving this because all topic participants were mentioned in #{{ stream_name }} > {{ topic_name }}.{% endtrans %}
+{% trans %}You are receiving this because all topic participants were mentioned in #{{ channel_name }} > {{ topic_name }}.{% endtrans %}
 {% elif stream_wildcard_mentioned_in_followed_topic %}
 {% trans %}You are receiving this because you have wildcard mention notifications enabled for topics you follow.{% endtrans %}
 {% elif topic_wildcard_mentioned %}
-{% trans %}You are receiving this because all topic participants were mentioned in #{{ stream_name }} > {{ topic_name }}.{% endtrans %}
+{% trans %}You are receiving this because all topic participants were mentioned in #{{ channel_name }} > {{ topic_name }}.{% endtrans %}
 {% elif stream_wildcard_mentioned %}
-{% trans %}You are receiving this because everyone was mentioned in #{{ stream_name }}.{% endtrans %}
+{% trans %}You are receiving this because everyone was mentioned in #{{ channel_name }}.{% endtrans %}
 {% elif followed_topic_email_notify %}
 {% trans %}You are receiving this because you have email notifications enabled for topics you follow.{% endtrans %}
 {% elif stream_email_notify %}
-{% trans %}You are receiving this because you have email notifications enabled for #{{ stream_name }}.{% endtrans %}
+{% trans %}You are receiving this because you have email notifications enabled for #{{ channel_name }}.{% endtrans %}
 {% endif %}
 
 {% if reply_to_zulip  %}

templates/zerver/emails/onboarding_zulip_topics.html

@@ -10,19 +10,19 @@
 </p>
 
 <p>
-    {{ _("In Zulip, <b>streams</b> determine who gets a message. <b>Topics</b> tell you what the message is about.")}} {{ _("Using topics, you can read Zulip one conversation at a time. You'll see each message in context, no matter how many different discussions are going on.") }}
+    {{ _("In Zulip, <b>channels</b> determine who gets a message. <b>Topics</b> tell you what the message is about.")}} {{ _("Using topics, you can read Zulip one conversation at a time. You'll see each message in context, no matter how many different discussions are going on.") }}
 </p>
 
-<img class="responsive-width" src="{{ email_images_base_url }}/streams-and-topics.png" alt="{{ _('Streams and topics in the Zulip app') }}"/>
+<img class="responsive-width" src="{{ email_images_base_url }}/streams-and-topics.png" alt="{{ _('Channels and topics in the Zulip app') }}"/>
 
 <p>
-    {{ _("To kick off a new conversation, just pick a stream and start a new topic. This way, the new conversation thread won't interrupt ongoing discussions. For a good topic name, think about finishing the sentence: “Hey, can we chat about…?”") }}
+    {{ _("To kick off a new conversation, just pick a channel and start a new topic. This way, the new conversation thread won't interrupt ongoing discussions. For a good topic name, think about finishing the sentence: “Hey, can we chat about…?”") }}
 </p>
 
 <img class="responsive-width" src="{{ email_images_base_url }}/day2_2.png" alt="{{ _('Examples of short topics') }}"/>
 
 <p>
-    {% trans %}Don't stress about picking the perfect name for your topic. If anything is out of place, it's easy to <a href="{{ move_messages_link }}">move messages</a>, <a href="{{ rename_topics_link }}">rename topics</a>, or even <a href="{{ move_topic_to_different_stream_link }}">move a topic to a different stream</a>.{% endtrans %}
+    {% trans %}Don't stress about picking the perfect name for your topic. If anything is out of place, it's easy to <a href="{{ move_messages_link }}">move messages</a>, <a href="{{ rename_topics_link }}">rename topics</a>, or even <a href="{{ move_channels_link }}">move a topic to a different channel</a>.{% endtrans %}
 </p>
 
 <a class="button" href="{{ realm_uri }}">{{ _("Go to Zulip") }}</a>

templates/zerver/emails/onboarding_zulip_topics.txt

@@ -1,10 +1,10 @@
 {{ _("Here are some tips for keeping your Zulip conversations organized with topics.") }}
 
-{{ _("In Zulip, streams determine who gets a message. Topics tell you what the message is about.") }} {{ _("Using topics, you can read Zulip one conversation at a time. You'll see each message in context, no matter how many different discussions are going on.") }}
+{{ _("In Zulip, channels determine who gets a message. Topics tell you what the message is about.") }} {{ _("Using topics, you can read Zulip one conversation at a time. You'll see each message in context, no matter how many different discussions are going on.") }}
 
-{{ _("To kick off a new conversation, just pick a stream and start a new topic. This way, the new conversation thread won't interrupt ongoing discussions. For a good topic name, think about finishing the sentence: “Hey, can we chat about…?”") }}
+{{ _("To kick off a new conversation, just pick a channel and start a new topic. This way, the new conversation thread won't interrupt ongoing discussions. For a good topic name, think about finishing the sentence: “Hey, can we chat about…?”") }}
 
-{% trans %}Don't stress about picking the perfect name for your topic. If anything is out of place, it's easy to move messages ({{ move_messages_link }}), rename topics ({{ rename_topics_link }}), or even move a topic to a different stream ({{ move_topic_to_different_stream_link }}).{% endtrans %}
+{% trans %}Don't stress about picking the perfect name for your topic. If anything is out of place, it's easy to move messages ({{ move_messages_link }}), rename topics ({{ rename_topics_link }}), or even move a topic to a different channel ({{ move_channels_link }}).{% endtrans %}
 
 
 {{ _("Go to Zulip") }}:

zerver/lib/email_notifications.py

@@ -527,7 +527,7 @@ def do_send_missedmessage_events_reply_in_zulip(
         context.update(narrow_url=narrow_url)
         topic_resolved, topic_name = get_topic_resolution_and_bare_name(message.topic_name())
         context.update(
-            stream_name=stream.name,
+            channel_name=stream.name,
             topic_name=topic_name,
             topic_resolved=topic_resolved,
         )
@@ -852,7 +852,7 @@ def enqueue_welcome_emails(user: UserProfile, realm_creation: bool = False) -> N
             unsubscribe_link=unsubscribe_link,
             move_messages_link=realm_url + "/help/move-content-to-another-topic",
             rename_topics_link=realm_url + "/help/rename-a-topic",
-            move_topic_to_different_stream_link=realm_url + "/help/move-content-to-another-stream",
+            move_channels_link=realm_url + "/help/move-content-to-another-stream",
         )
 
         send_future_email(